To prepare crust, combine crumbs, margarine, and sugar in a mixing bowl. Press mixture firmly in a 9" pie pan. Chill one hour, or until firm. Or, bake in a 350 oven for ten minutes or until lightly browned. Cool on rack before filling. To prepare filling, combine whipped topping mixes and one cup milk according to package directions. Add remaining milk and pudding mixes. Mix until smooth. Spoon one half into crust, spreading evenly. Drizzle two tablespoon syrup over top and sprinkle with two tablespoons walnuts. Spoon remaining filling mixture over top walnuts. Drizzle remaining syrup and sprinkle walnuts on top. Freeze for four hours, or until firm. Store leftovers in freezer.